Automatic gravity stoker



Aug. 23, 1938. J. K.` DUKAs 2,128,125.

AUTOMATIC GRAVITY STOKER Filed Nov. 5, 1955 Patented Aug. 23, 1938 UNITED STATES PATENT OFFICE James K. Dukas, Kingston, Pa.

Application November 5, 1935, Serial No. 48,429

1 Claim.

This invention relates to automatic gravity stokers for furnaces and the like, and has for one of its objects the production of a simple and eiiicient means for automatically and through gravity, feeding fuel to the lire-box of a furnace and the like.

Another object of this invention is the production of a simple and efficient means for automatically cutting off the iiow of fuel to the nrebox of a furnace and the like, when the blower is in operation, and then automatically opening the fuel feed when the blower discontinues operation.

A further object of this invention is the production of a simple and efficient gravity feed automatic fuel Stoker for furnaces, boilers, and the like, wherein the fuel feed may be automatically opened and closed through thestarting and stopping of the blower.

Other objects and advantages of the present invention will appear throughout the following specification and claim.

In the drawing:

Figure 1 is a fragmentary top plan view of a furnace showing the improved automatic gravity Stoker -in position; v

Figure 2 is a side elevation of a furnace Showing the gravity automatic Stoker and actuating means, `a portion of the furnace being broken away and shown in section;

Figure 3 is a longitudinal section taken through the bottom of the feeding hopper and valve mechanism on line 3 3 of Figure l;

Figure 4 is a transverse sectional View taken on line 4 4 of Figure l;

Figure 5 is a horizontal sectional view through the blower tube showing the valve actuating fan carried thereby;

Figure 6 is a side elevation illustrating a modified form of gravity automatic Stoker;

Figure 7 is a section taken on line 'l-'l of Figure 6;

Figure 8 is a side elevationv showing a modified form of automatic control for actuating the operating lever of the automatic stoker.

By referring to the drawing, it will be seen that Ill designates the furnace boiler or similar heating medium which may be of the conventional type common to the trade. In connection with the furnace ID I employ a blower II of the conventional type actuated by a motor I2, which motor I2 is controlled through the medium of a thermostat I3 located in a room above or in any other convenient place to thermostatica'lly control the operation of the motor I2. A blower tube I4 is connected to the furnace through the ash pit or in any other convenient manner and this blower tube I4 is provided with a wind motor housing I5 which housing I5 communicates directly with the blower I I, as shown in Figure I, a

wind motor I6 being mounted within the wind I motorhousing I5 for the purpose hereinafter described.

I preferably mount the gravity fuel feeding mechanism upon a platform Il which rests upon the top of the furnace I0, asshown, the platform I 'l having a depending and right-angularly extending face plate I8 overhanging the side of the furnace I, as shown in Figure 2, for the purpose of supporting the working parts of the gravity Stoker mechanism. The platform il is provided with a plurality of ports I9 throughv which extend the feed tubes which may be of any numberk desired, and preferably from three to six inches in diameter, the size being varied to suit the particular condition and type of coal being used. The feed tubes 20 extend down through `the roof 2| of the fire-box 22 for a substantial distance beyond the lower face of ythe tube, as shown in Figure 2, in order to provide a space above the normal layer of fuel in the rebox whereby the gas may easily pass out through the flue 23.

A fuel hopper or bin 24 is mounted uponthe platform Il and carries a bottom 25 having feeding ports 26 which communicate with the `feed tubes or pipes 20. A valve plate 2l is slidably mounted between the bottom 25 and the platform Il, and this Valve plate 2l is provided with ports 28 which are adapted to be brought into registration with the ports 25 and the feed tubes or pipes ZI) and allow the fuel within the hopper or bin 24 to drop through gravity down through the feed tubes or pipes 20 into the re-box 22.

The valve plate 21 is mounted to freely reciprocate between the bottom 25 and the platform Il and operating levers 29 are pivotally connected to the respective ends of the valve plate 2l, as shown in Figure l, and these levers 29 are connected by a connecting link 3| which connecting link 3Ir is engaged at its respective ends by the chains 32. These chains 32 are connected near the respective ends of the rock lever 33, which lever 33 is pivoted, as at 34, to the depending angularly extending face plate I8.

A weight 35 is connected to one end of the rock lever 33 and the opposite end of the rock lever 33 is connected to a flexible element or cable 36 which cable 36 is wound about a drum 3l carried by the supporting shaft 38 of the fan I6, shown in detail in Figure 5. The chains 32 as shown in Figure 1, preferably extend around guiding pulleys 39 mounted in any desired or convenient manner upon the body of the furnace or boiler I0. L

The operation of the device is as follows:-

Several days supply of coal of the pulverized variety such as buckwheat and finer qualities, which may be purchased on the market at the cheapest rate, is placed within the bin or hopper 24. When the thermostat I3 starts the motor I2, the blower II will be actuated, driving the wind motor I6, thereby winding the cable 36 upon the drum 31 which will cause the cable 36 to pull downwardly on one end of the rock lever 33, lifting the weight 35 and moving the valve plate 21 to a point where the ports 28 will be out of registration with the ports 26 and feeding tubes or pipes 20 cutting off the fuel supply of the hopper 24 while the blower I I is in operation. In this way, the draft through will be prevented from being forced up through the tubes 20 and into the hopper in order to prevent an explosion of gases through the tube and hopper. As soon as the thermostat I3 cuts off the motor I2 and the operation of the blower II is stopped or the blower II is rendered inactive, the weight 35 will cause the rock lever 33 to return to its normal or substantially horizontal position, thereby bringing the ports 28 of the valve plate 21 into registration with the ports 26 and feeding tubes 20, allowing the pulverized fuel from the hopper 24 to pass down through the feed tubes or pipes 20 and into the fire-box 22.

It will therefore be seen from the foregoing description and by considering the drawing, that the supply of fuel through the tubes 2B will be cut off while the blower II is in operation, but as soon as the blower II has discontinued its operation or is rendered inactive, the valve plate 21 will move to an open position allowing the fuel to pass down through the tubes or pipes to into the fire-box 22.

In Figures 6 and 7 there is shown a modified form of the invention wherein the furnace 40 carries a hopper 4I for feeding fuel to the firebox 42 of the furnace 4U through an inclined feeding tube or chute 43. This chute 43 carries a valve box 44 in which works an apertured control gate 45 which gate is actuated through the medium of an operating lever 46 connected to a cable 36a, similar to the cable 36, which cable 36ais actuated in a manner similar to that as illustrated in Figures 1 and 2 through the medium of a wind motor mounted in the housing I5a similar to the housing I5, and a drum 31a.

A weight 35a is connected to the control gate 45 to bring the feeding aperture 41 into registration with the feeding tube 43 and tension is released from the pull cable 36a.

It should be understood that the wind motor I6 mounted within the wind motor housing I5, as well as the wind motor mounted within the wind motor housing I5a will keep the cables 36 and 36a wound upon their respective drums, as long as the blast of air passing from the blower against the wind motor continues, since this blast will prevent the wind motor from reversing. This will allow the passage of air from the blower through the blower tube even though the cables are wound to their limit upon the respective drums.

In Figure 8 there is shown a further modified form of the invention wherein in place of the wind motor housing I5 and wind motor I6, I employ a governor 48 which is actuated by the motor I2a, the governor 48 being connected to the cable 36h which cable in turn is connected to the rock lever 33h.

Certain detail changes in the mechanical construction, combination and arrangement of parts may be employed without departing from the spirit of the invention, so long as such changes fall within the scope of the appended claim.

Having described the invention what is claimed as new isz- In combination with a furnace having a firebox, a blower, a fuel supply hopper located above the furnace and having discharge openings for supplying fuel from the hopper to the fire-box of the furnace, a support for said hopper having a depending apron atk one side, a valve plate slidable into and out of position for opening and closing said discharge openings, a rock lever pivotally connected to said apron and extending longitudinally of the apron and the valve, flexible connection between ends of the lever and ends of the valve for sliding the valve as said rock lever is swung, a weight connected to one end of the rock lever for automatically moving the valve in one direction, means driven in conjunction with the blower for moving the rock lever in the opposite direction, said last mentioned means comprising a wind motor actuated by a blast of air from the blower, a shaft supporting the wind motor, a drum carried by the shaft, and a exible cable Wound upon the drum and to be connected to the opposite end of said rock lever from said weight for tilting the lever and moving the Valve to an adjusted position.

JAMES K. DUKAS. 

